This invention relates to milk-based food products, and in particular to the microdispersal of vitamin E in milks (milkfat-based milk, skim milk, vegetable oil-filled milk, and blends thereof) at a level providing at least 31 IU (International Units) per serving.
The information provided herein is solely to assist the understanding of the reader; none of that information or cited references is admitted to be prior art to the present invention.
In the past five years several major prospective health studies have been published demonstrating that vitamin E supplement ingestion is associated with a reduced risk of coronary heart disease (CHD) in both women and men (e.g., Stampfer et al., NEJM, 328 1444-1449, 1993 Rimm et al., NEJM, 328, 1450-1456, 1993). In a four year study of nearly 40,000 males, Rimm et al., showed that the risk of CHD diminished significantly as the daily supplemental level of vitamin E increased. This study indicates that the current Recommended Daily Allowance (RDA) of 30 international units (IU) of vitamin E is insufficient for obtaining the full protective benefits of vitamin E. In fact, the study data suggest that for most adult males, a daily supplement of at least 100 IU of vitamin E is appropriate for helping to protect against CHD. In another prospective study, long-term ingestion of vitamin E was tested for its ability to reduce the incidence of myocardial infarction in patients having a documented condition of coronary atherosclerosis (Stephens et al., Lancet, 347, 781-786, 1996). In this study, it was shown that sustained supplementation of the patients' diets with 400 IU of RRR-.alpha.-tocopherol ingested once per day in capsules was sufficient to reduce the risk of non-fatal heart attacks by 77%. This protective effect became apparent after about 200 days of treatment with the vitamin. In still another study (Losonczy et al., Am. J. Clin. Nutr. 64, 190-196, 1996), individuals in an elderly population (n=11,178) aged 67-105, were each followed for 6 years, and their uses of vitamin E and/or vitamin C supplements were correlated with their risk of developing cancer and CHD. While vitamin C supplements could not be shown to have a significant protective effect over the 6 year period, vitamin E supplements (greater than 100 IU per day) were shown to reduce all-cause mortality 27-34%, CHD mortality 41-47%, and cancer mortality 22-23% (in these ranges, the first number is the age and sex-adjusted risk, and the second is a multi-covariable adjusted risk).
Many other studies have shown the beneficial function of vitamin E for protecting plasma LDL cholesterol and cellular components against oxidative damage, and for maintaining normal immunological function to protect the body against disease. It has also been shown in an 88 subject study, that even high daily doses of vitamin E ingested by healthy elderly people for extended periods of time (i.e., 800 IU per day for 4 months), caused no side-effects, no negative changes in general health or metabolic functions based upon an extensive battery of blood tests (Meydani et al., Am. J. Clin. Nutr. 68: 311-318, 1998). By contrast, significant improvements in T cell mediated function and significant increases in plasma vitamin E levels were noted. In that study, subjects consuming 800 IU of vitamin E per day for 4 months, reached plasma vitamin E levels of up to 71.5 .mu.mol per liter (3075 .mu.g per deciliter). This 3000 .mu.g per deciliter level is usually considered the "saturation level" for vitamin E transport by lipoproteins in humans regularly consuming high doses of vitamin E, and is essentially 3.0.times. the basal fasting plasma level of vitamin E (800-1000 .mu.g per deciliter) measured in the general population consuming no vitamin E dietary supplements.
As a result of a consensus in the scientific community on the benefits of supplemental vitamin E, a number of "structure-function" health claims for vitamin E have been approved under the Dietary Supplement Health and Education Act (DSHEA) in the U.S. While the DSHEA does not encompass foods per se, in the last five years a number of food products supplemented or "fortified" with low levels of vitamin E have come to market. By the term "low levels" it is meant that these foods provide quantities of vitamin E which are less than or equal to the current RDA of 30 IU of vitamin E per serving of the food. Typically, vitamin E is added to foods in one of its more chemically stable forms, e.g., .alpha.-tocopherol acetate (also known as .alpha.-tocopheryl acetate). Four different forms of vitamin E (the alcohol and ester forms of synthetic racemic (rac) vitamin E and the alcohol and ester forms of natural (RRR) vitamin E) are commercially available, and because of their differences in bioactivities and molecular weights, are assigned different values of specific activity (IU per milligram) according to the National Formulary as follows:
1 mg all-rac-.alpha.-tocopherol acetate=1.00 IU PA1 1 mg all-rac-.alpha.-tocopherol=1.10 IU PA1 1 mg RRR-.alpha.-tocopherol acetate=1.36 IU PA1 1 mg RRR-.alpha.-tocopherol=1.49 IU PA1 (i) When vitamin E is microdispersed in milk, fat is not required in the milk product for hyper-efficient vitamin E absorption into the bloodstream. Thus, vitamin E dispersed in skim milk is as hyper-efficiently absorbed into the bloodstream as vitamin E dispersed in regular 1% milk. PA1 (ii) The presence of a substantial proportion of polyunsaturated fats such as soybean oil, which generally inhibit vitamin E absorption, have been shown to produce no such inhibitory effect when co-dispersed with vitamin E in milk. Thus, non-hydrogenated polyunsaturated vegetable oil-containing filled milks can serve as efficient carriers for vitamin E supplements. PA1 (iii) Ingestion of a vitamin E dose microdispersed in milk was found to be approximately 2-3 times more effective than the same dose ingested in capsule form for vitamin E doses exceeding approximately 50 IU per day. Thus, ingesting 100 IU of all-rac-.alpha.-tocopherol acetate microdispersed in milk for 2-4 weeks demonstrated an equivalency of ingesting 300 IU of the same vitamin in the form of soft gel capsules in terms of elevating plasma and LDL levels of vitamin E. PA1 (iv) Ingestion of a vitamin E dose of less than 50 IU per day microdispersed in milk, had a diminishing advantage over the same dose ingested in capsule form. In fact, with a dose of 30 IU vitamin E per day, it has been calculated that milk provides at most only a 38% greater increase (which is not a statistically significant increase) in the ratio of vitamin E/cholesterol than that which would achieved by ingesting one 30 IU vitamin E capsule. PA1 (v) A dose of vitamin E microdispersed in orange juice was found to be much less efficiently absorbed and/or absorbed into lipoproteins than the same dose microdispersed in milk. In fact, with 200 IU of all-rac-.alpha.-tocopherol acetate provided daily in orange juice, the increase in plasma vitamin E after 4 weeks was less than that achieved with 100 IU provided daily in milk.
In a separate area of nutritional biochemistry, Perlman et al. in U.S. Pat. No. 5,514,407 combined vegetable oils rich in polyunsaturated fatty acids, with cholesterol-reduced animal fats rich in saturated fatty acids to produce oxidation-resistant fat blends containing 1-10 parts by weight of the animal fat to 1 part of vegetable oil. These blends showed favorable nutritional characteristics in mammals, including a decreased total serum cholesterol level, and a decreased LDL/HDL cholesterol ratio in humans. In Sundram et al., U.S. Pat. No. 5,578,334 and Sundram et al., U.S. Pat. No. 5,843,497 (which are hereby incorporated by reference in their entireties including drawings), certain vegetable oils such as soybean oil, rich in polyunsaturated fatty acids, were combined with palm oil, rich in saturated fatty acids, to produce dietary fat blends containing approximately equal proportions of saturated and polyunsaturated fatty acids (hereinafter termed "balanced fats"). Compared to diets in which one class of fatty acids predominates (polyunsaturated, monounsaturated or saturated), if such balanced fats are consumed as the principal dietary fat (at approximately 30% of dietary calories supplied as fat), the ratio of plasma LDL to HDL cholesterol is beneficially reduced. At the same time, HDL levels are beneficially sustained or increased.